Synthesis and Tribological Characteristics of High-Performance Self-Lubricating CoCrFeNiMox-Ni/MoS2-Ag-Cr2O3 Composites
Year: 2026
Type: article
Abstract: High-temperature self-lubricating materials with stable tribological performance across a wide temperature range are essential for advanced mechanical systems under extreme conditions. However, balancing mechanical strength and lubrication efficiency remains a key challenge. This study fabricated CoCrFeNiMox-Ni/MoS2-Ag-Cr2O3 composites (x = 0.2, 0.5, 1) via spark plasma sintering, aiming to investigate the effect of Mo content on their microstructure, mechanical properties, and tribological behavior. Microstructural analysis showed that the as-sintered composites mainly consist of FCC phase, Cr2O3, Ag, and Ni/MoS2. Increasing Mo content from 0.2 to 1 wt.% significantly promoted the formation of hard σ-phase intermetallics, leading to increased hardness (up to 546 HV) and yield strength (peaking at 502 MPa). Tribological tests at 25–800 °C indicated continuous lubrication behavior in all composites. The minimum friction coefficient was 0.23, and wear rates remained below 10−6 mm3/N·m. In the low-to-medium temperature range, lubrication was dominated by the synergistic effect of Ni/MoS2 and Ag: Ni/MoS2 formed low-shear-strength films, while Ag reduced surface adhesion. Meanwhile, the Mo solid solution strengthened and the σ-phase enhanced wear resistance by improving hardness and inhibiting plastic deformation. At high temperatures, tribochemical reactions generated lubricating films composed of oxides and molybdates, which maintained tribological performance by reducing direct contact between friction pairs. This study demonstrates that Mo-doped high-entropy alloy composites can serve as high-performance wide-temperature self-lubricating materials, providing a basis for designing “matrix-lubricant” systems for extreme-temperature applications.
Source: Materials
DOI: 10.3390/ma19040783
Authors: Bei Sun, Zhiming Gao, Zhongtang Gao
Language: English
Topic: High Entropy Alloys Studies
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,137
OpenAlex ID: W7130330398